JP2021190931A - Vibration piece and frequency adjustment method - Google Patents

Abstract

To provide a vibration piece and a frequency adjustment method having a large frequency adjustment amount.SOLUTION: A vibration piece 1 includes: a base 21; a first arm 22 that continues from the base 21; a second arm 23 that continues from the base 21; a first beam 25 that has a first portion 25a connected with the first arm 22, and a second portion 25b connected with the second arm 23, opposite to the first portion 25a, and located on an extension line of the first portion 25a; first electrodes 42 that are arranged on the first arm 22 and the second arm 23; piezoelectric layers 43 that are arranged on the first electrodes 42; and second electrodes 44 that are arranged on the piezoelectric layers 43.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibrating piece and a frequency adjusting method.

In an oscillator having a vibrating arm, a vibrating piece that vibrates in the thickness direction of the vibrating arm, that is, so-called out-of-plane vibration, is known, instead of the vibrating arm vibrating in the plane. This vibrating piece generally has an odd number of vibrating arms, and when it has three or more vibrating arms, it performs vibration in which adjacent vibrating arms alternately repeat vibrations in opposite directions, so-called walk mode vibration.
The frequency of the tuning fork type oscillator that performs in-plane vibration and out-of-plane vibration is adjusted by providing a weight at the tip of the vibrating arm and irradiating this weight with a laser or the like to remove a part of the weight. .. This removes a part of the weight and reduces the weight of the vibrating arm to gradually increase the frequency and adjust the frequency.
On the other hand, the vibrating piece described in Patent Document 1 is provided with a second mass portion serving as a weight at the tip of the vibrating arm, and has a length from the end to the tip of the vibrating arm on the base side. A first mass part serving as a weight is provided at the substantially center of the arm. The frequency can be adjusted to be higher by removing a part of the vibrating arm of the first mass part on the tip side, and the frequency can be adjusted by removing a part of the base side of the vibrating arm of the first mass part. It can be adjusted to be low. Therefore, the frequency of the vibrating piece can be adjusted with high accuracy.

Japanese Unexamined Patent Publication No. 2011-155628

However, the vibrating piece described in Patent Document 1 is capable of highly accurate frequency adjustment by removing a part of the first mass part and the second mass part, and is suitable for frequency adjustment with a small frequency adjustment amount. However, when the frequency adjustment amount is large, there is a problem that the frequency adjustment cannot be performed because the frequency adjustment amount is small.

The vibrating piece is connected to the base, the first arm continuous with the base, the second arm continuous with the base, the first portion connected to the first arm, and the second arm. A first beam having a second portion facing the first portion and located on an extension of the first portion, a first electrode arranged on the first arm and the second arm, and the first electrode. A second electrode arranged on the piezoelectric layer and a second electrode arranged on the piezoelectric layer are included.

The frequency adjusting method is a frequency adjusting method for the vibrating piece, and the vibrating piece includes a base, a first arm continuous with the base, a second arm continuous with the base, and the first arm and the second arm. A first beam connecting the arm, a first electrode arranged on the first arm and the second arm, a piezoelectric layer arranged on the first electrode, and a first arranged on the piezoelectric layer. The frequency adjusting method includes two electrodes, and the frequency adjusting method includes a step of changing the oscillation frequency of the vibrating piece by cutting the first beam.

The schematic plan view which shows the structure of the vibrating piece which concerns on 1st Embodiment. FIG. 1 is a schematic cross-sectional view taken along the line AA of FIG. FIG. 1 is a schematic cross-sectional view taken along the line BB of FIG. The schematic plan view which shows the structure of the vibrating body before frequency adjustment. The figure explaining the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The flowchart which shows the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The schematic plan view which shows the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The schematic plan view which shows the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The schematic plan view which shows the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The schematic plan view which shows the frequency adjustment method of the vibrating piece which concerns on 1st Embodiment. The schematic plan view which shows the structure of the vibrating body before the frequency adjustment of the vibrating piece which concerns on 2nd Embodiment.

1. 1. First Embodiment First, the vibration piece 1 according to the first embodiment will be described with reference to FIGS. 1, 2, and 3.

The vibrating piece 1 according to the present embodiment can be manufactured by processing an SOI (Silicon on Insulator) substrate 10. The SOI substrate 10 is a substrate in which a silicon substrate 11, an embedded oxide film (BOX: Buried Oxide) 12, and a surface silicon layer 13 are laminated in this order. For example, the silicon substrate 11 and the surface silicon layer 13 are made of single crystal silicon (Si), and the embedded oxide film 12 is made of silicon dioxide (SiO ₂ ) or the like. In the present embodiment, the surface silicon layer 13 corresponds to the base material constituting the base portion 21, the first arm 22, the second arm 23, and the third arm 24.

As shown in FIGS. 1, 2, and 3, the vibrating piece 1 is composed of a silicon substrate 11, an embedded oxide film 12 arranged in a partial region of the silicon substrate 11, and silicon on the surface silicon layer 13. The vibrating body 20 is formed, the temperature characteristic adjusting film 30 arranged in a predetermined area of the vibrating body 20, the piezoelectric drive unit 40 arranged in a predetermined area of the temperature characteristic adjusting film 30, and a predetermined vibrating body 20. It includes a metal film 50 for frequency adjustment arranged in the region.

The vibrating body 20 has a base 21 supported by the embedded oxide film 12, a first arm 22, a second arm 23, and a second arm 23 separated from surrounding silicon other than the base 21 on the region where the embedded oxide film 12 has been removed. It has a third arm 24 and. That is, the vibrating body 20 has a base 21 and a first arm 22, a second arm 23, and a third arm 24 made of silicon continuous with the base 21. In the example shown in FIGS. 1 to 3, the vibrating body 20 has three arms 22, 23, 24. A cavity 11a is formed on the silicon substrate 11 at a position facing the arms 22, 23, 24.

The vibrating body 20 is provided with five frequency adjusting beams between the first arm 22 and the second arm 23. A first beam 25, a second beam 26, a third beam 27, a fourth beam 28, and a fifth beam 29 are provided from the tip end side of the arms 22 and 23 toward the base portion 21. In FIG. 1, the first beam 25, the second beam 26, the third beam 27, and the fourth beam 28 are cut by a laser in order to obtain a desired frequency. Therefore, the first beam 25 is connected to the first arm 22 and the second arm 23, faces the first portion 25a, and is located on the extension line of the first portion 25a. It has a portion 25b and. Similarly, the second beam 26, the third beam 27, and the fourth beam 28 also have a portion connected to the first arm 22 and a portion connected to the second arm 23 and connected to the first arm 22, respectively. It has a portion facing each other and located on an extension of the portion connected to the first arm 22.

The first beam 25 is arranged between the base 21 and the center of the arms 22, 23, 24 in the longitudinal direction. That is, as shown in FIG. 4 described later, the first beam 25 has the center line C and the base 21 with respect to the center line C of the total length in the longitudinal direction between the tips of the arms 22, 23, 24 and the base 21. It is placed between and. Therefore, the second beam 26, the third beam 27, the fourth beam 28, and the fifth beam 29 are arranged between the first beam 25 and the base portion 21.

Further, in the present embodiment, four beams for frequency adjustment are arranged between the first beam 25 and the base 21, but the present invention is not limited to this, and one or more and seven or less beams are used. All you need is. Therefore, each of one or more and seven or less beams arranged between the first beam 25 and the base 21 connects the first arm 22 and the second arm 23, or the first arm 22. It has a portion connected to the second arm 23, a portion facing the portion connected to the first arm 22, and a portion located on an extension of the portion connected to the first arm 22. Either.

Further, five beam for frequency adjustment are also provided between the second arm 23 and the third arm 24, and these beams are used as the first beam between the first arm 22 and the second arm 23. Similar to the beam 25, the second beam 26, the third beam 27, and the fourth beam 28, the frequencies of the first arm 22, the second arm 23, and the third arm 24 are set to the desired frequencies by cutting with a laser. Can be adjusted to.

The temperature characteristic adjusting film 30 is made of silicon dioxide (SiO ₂ ). The temperature characteristic adjusting film 30 is provided to correct the frequency temperature characteristic of the frequencies of the arms 22, 23, and 24. Silicon has a frequency temperature characteristic in which the frequency decreases as the temperature rises, while silicon dioxide (SiO ₂ ) has a frequency temperature characteristic in which the frequency increases as the temperature rises. Therefore, by arranging the temperature characteristic adjusting film 30 which is silicon dioxide on the arms 22, 23, 24 of the vibrating body 20 of silicon, the arm 22, 23, 24 of the vibrating body 20 and the temperature characteristic adjusting film 30 are composed. The frequency-temperature characteristic of the frequency of the complex to be formed can be brought close to flat. Specifically, for example, the amount of change in the frequency of the vibrating body 20 in the temperature range of -25 ° C to + 75 ° C is flattened to about ± 3,000 ppm by forming the temperature characteristic adjusting film 30 to about ± 200 ppm to about ± 500 ppm. Can be transformed into.

The silicon dioxide constituting the temperature characteristic adjusting film 30 is formed by a thermal oxidation method or a CVD (Chemical Vapor Deposition) method in which the surface silicon layer 13 is thermally oxidized.

The piezoelectric drive unit 40 includes a polysilicon film 41, a first electrode 42, a piezoelectric layer 43, a second electrode 44, and a plurality of wirings 45. The polysilicon film 41 is made of polysilicon that is not doped with impurities, and may be made of amorphous silicon, for example. In the present embodiment, the polysilicon film 41 and the vibrating body 20 cover the temperature characteristic adjusting film 30. Thereby, the polysilicon film 41 can protect the temperature characteristic adjusting film 30 from the etching of silicon dioxide around the piezoelectric drive unit 40.

The first electrode 42 and the second electrode 44 are arranged so as to sandwich the piezoelectric layer 43. That is, the first electrode 42 arranged on the side opposite to the temperature characteristic adjusting film 30 of the polysilicon film 41, the piezoelectric layer 43 arranged on the side opposite to the polysilicon film 41 of the first electrode 42, and the piezoelectric layer. The second electrode 44 arranged on the side opposite to the first electrode 42 of the body layer 43 is laminated in this order. In the example shown in FIGS. 1 to 3, three sets of the first electrode 42, the piezoelectric layer 43, and the second electrode 44 are provided corresponding to the three arms 22, 23, and 24.

The plurality of wires 45 are electrically connected to the first electrode 42 and the second electrode 44 so as to vibrate the adjacent arms 22, 23, and 24 in opposite phases. Further, the plurality of wirings 45 are electrically connected to the electrode pads 46, and by applying a voltage from the outside between the two electrode pads 46, the adjacent arms 22, 23, and 24 are vibrated in opposite phases. Can be done.

As materials constituting these, for example, the piezoelectric layer 43 is made of aluminum nitride (AlN) or the like, and the first electrode 42 and the second electrode 44 are made of titanium nitride (TiN) or the like. The wiring 45 and the electrode pad 46 are made of aluminum (Al), copper (Cu), or the like.

When a voltage is applied between the first electrode 42 and the second electrode 44 via the two electrode pads 46, the piezoelectric layer 43 expands and contracts, causing the arms 22, 23, and 24 to vibrate. The vibration is greatly excited at its own frequency and the impedance is minimized. As a result, the oscillator using the vibration piece 1 oscillates at an oscillation frequency mainly determined by the frequencies of the arms 22, 23, and 24.

The metal film 50 is arranged on the polysilicon film 41 at the tips of the arms 22, 23, and 24. The metal film 50 is provided to adjust the frequency of the arms 22, 23, 24, and the frequency is reduced by irradiating a part of the metal film 50 with a laser to remove the metal film 50 and reducing the weight of the arms 22, 23, 24. Is gradually increased to adjust the frequency. Therefore, the metal film 50 has a cutting mark 51 removed by irradiating the laser to adjust the vibrating piece 1 to a desired frequency. The frequency adjustment amount that can be adjusted by removing the metal film 50 is 5,000 ppm to 8,000 ppm, although it depends on the film thickness of the metal film 50.

The material constituting the metal film 50 is, for example, gold (Au). Further, aluminum (Al) or the like may be used instead of gold.

As described above, in the present embodiment, a tripod-shaped vibrating piece 1 having three arms 22, 23, and 24 is taken as an example and described, but the number of a plurality of arms extending from the base 21 is limited. Not done.

Next, the frequency adjustment of the vibration piece 1 according to the present embodiment will be described with reference to FIGS. 4 and 5.
In the three-legged vibration piece 1 of the present embodiment, the frequency of the vibration piece 1 is f, the total length of the arms 22, 23, 24 is L, the thickness of the arms 22, 23, 24 in the vibration direction is t, and the out-of-plane vibration. Assuming that the frequency constant is K, there is a relationship of f = K × (t / L ^2). Here, K is a constant determined by Young's modulus, Poisson's ratio, and film density of the material constituting the arm, that is, the frequency f of the vibrating piece 1 that performs out-of-plane vibration is in the vibration direction of the arms 22, 23, and 24. It is proportional to the thickness t and inversely proportional to the square of the total length L of the arms 22, 23, 24. Therefore, by adjusting the length of the total length L of the arms 22, 23, 24, the frequency f of the vibrating piece 1 can be greatly changed.

Therefore, as shown in FIG. 4, the vibrating piece 1 of the present embodiment has 2 between the first arm 22 and the second arm 23 of the vibrating body 20 and between the second arm 23 and the third arm 24. A beam for adjusting the frequency for connecting the two arms is provided, and the first beam 25 is cut in order to lengthen the total length L of the arms 22, 23, 24, and the frequency f is lowered in order to reduce the vibration piece 1. Adjust the frequency.

Specifically, assuming that the width W1 which is the length in the lateral direction of the beam for frequency adjustment is 1 μm and the distance S1 between the beams is 1 μm, when one first beam 25 is cut, the arms 22 and 23 are used. , The total length L of 24 is increased by 2 μm, and the frequency corresponding to the length of 2 μm can be lowered. Further, when the first beam 25 and the second beam 26 are cut in two, the total length L of the arms 22, 23, 24 becomes 4 μm longer, and the frequency corresponding to the length of 4 μm can be lowered. In this embodiment, the width W1 of the first beam 25, the second beam 26, the third beam 27, the fourth beam 28, and the fifth beam 29, which are five beams for frequency adjustment, and the distance S1 between the beams are S1. , And the distance between the fifth beam 29 and the base 21 is 1 μm.

FIG. 5 shows a frequency adjustment method when the target frequency of the vibrating piece 1 is 32.768 kHz and the frequency of the manufactured vibrating piece 1 is 33.700 kHz, which is about 3% higher than the target frequency. The horizontal axis of FIG. 5 is the total length L of the arm, and the vertical axis is the frequency of the vibrating piece 1.

The vibration piece 1 before cutting the beam for frequency adjustment has a frequency f0. When one of the first beams 25 is cut, the frequency drops by about 0.25 kHz to the frequency f1, and when the second beam 26 is cut, the frequency is further reduced. It drops by 0.25 kHz to a frequency f2, and when it is cut to the third beam 27, it further drops by about 0.25 kHz to a frequency f3, and when it is cut to the fourth beam 28, it further drops by about 0.25 kHz to a frequency f4. Here, the frequency f4 is 32.700 kHz, and the target frequency is lower than 32.768 kHz. Therefore, a part of the metal film 50 provided at the tips of the arms 22, 23, and 24 is removed to reduce the frequency. By adjusting the frequency to a high value, the frequency becomes f5. The frequency f5 is 32.768 kHz and can be adjusted to the target frequency.

Therefore, by providing a plurality of frequency adjusting beams between the arms 22, 23, and 24 and cutting the frequency adjusting beams, the frequency adjustment amount within the frequency adjustment range can be increased. That is, the range in which the frequency can be adjusted by cutting the beam for frequency adjustment is the coarse adjustment range in which the frequency adjustment amount is large, and the range in which the frequency can be adjusted by removing the metal film 50 is the fine adjustment range in which the frequency adjustment amount is small. Will be.

In the case of the vibration piece 1 of the present embodiment, the metal film 50 for fine adjustment adjusts 0.75% (7,000 ppm), which is 0.25 kHz, which changes by cutting one beam for frequency adjustment. The area and film thickness can be set.

As described above, according to the vibration piece 1 according to the present embodiment, a beam for frequency adjustment is provided between the first arm 22 and the second arm 23 and between the second arm 23 and the third arm 24. By cutting the frequency adjusting beam with a laser, the total length of the arms 22, 23, 24 can be lengthened, and by lowering the frequency of the vibrating piece 1, the vibrating piece 1 can be increased. The frequency can be adjusted. Therefore, since the first beam 25 near the tip end side of the first arm 22 and the second arm 23 is cut for frequency adjustment, the first portion 25a connected to the first arm 22 and the second arm 23 are cut. It has a second portion 25b, which is connected to the first portion 25a, faces the first portion 25a, and is located on an extension line of the first portion 25a. Further, by providing a large number of beams for frequency adjustment, the amount of frequency adjustment can be increased, and the frequency of the vibrating piece 1 having a frequency greatly deviated from the desired frequency to the high frequency side can be adjusted. Therefore, it is possible to obtain the vibration piece 1 having a large frequency adjustment amount.

Next, the frequency adjustment method of the vibration piece 1 according to the present embodiment will be described with reference to FIGS. 6 to 10.

As shown in FIG. 6, the frequency adjustment method of the vibrating piece 1 includes a vibrating piece preparation step of preparing the vibrating piece 1, a frequency measuring step of measuring the oscillation frequency of the vibrating piece 1, and adjusting the oscillation frequency of the vibrating piece 1. It includes a frequency coarse adjustment step, a frequency measurement step of measuring the oscillation frequency of the packaged vibration piece 1, and a frequency fine adjustment step of adjusting the oscillation frequency of the vibration piece 1.

1.1 Vibration piece preparation step First, in step S1, as shown in FIG. 7, a temperature characteristic adjusting film 30, a piezoelectric drive unit 40, a metal film 50, and the like are formed on a vibrating body 20 having a beam for frequency adjustment. The vibrating piece 1 is prepared. The vibrating piece 1 may be a single piece, but in consideration of mass productivity and manufacturing cost of the vibrating piece 1, from a large board to a large board capable of manufacturing a plurality of vibrating pieces 1 by a batch processing method. The formed vibration piece 1 may be used.

1.2 Frequency measurement step Next, in step S2, for example, a prober of a frequency measuring device having an oscillation circuit is brought into contact with an electrode pad 46 provided on the vibration piece 1, and the oscillation frequency of the vibration piece 1 is measured.

1.3 Frequency coarse adjustment step Next, in step S3, based on the measured oscillation frequency, the frequency adjustment beam provided on the vibration piece 1 is cut with a laser to reduce the oscillation frequency, so that the vibration piece 1 Adjust the oscillation frequency of. For example, if the target frequency of the vibrating piece 1 is 32.768 kHz and the oscillation frequency is 33.700 kHz, which is about 3% higher than the target frequency, cutting one beam for frequency adjustment lowers the frequency by about 0.25 kHz. If the width W1 and the interval S1 of the frequency adjusting beam are set so as to be performed, the frequency can be lowered by about 1.00 kHz by cutting four frequency adjusting beams. Therefore, as shown in FIGS. 8 and 9, the oscillation frequency of the vibrating piece 1 can be adjusted to about 32.700 kHz by irradiating the laser from the first beam 25 to the fourth beam 28 in order and cutting the laser. .. In this way, by cutting the first beam 25 and one or more frequency adjusting beams arranged between the first beam 25 and the base 21 by the number corresponding to the measured oscillation frequency, the vibrating piece. It can be adjusted by changing the oscillation frequency of 1, specifically by lowering it.

1.4 Frequency measurement step Next, in step S4, the vibrating piece 1 adjusted to about 32.700 kHz is hermetically sealed in a package or the like in a vacuum state, and for example, the prober of the frequency measuring device having an oscillation circuit is vibrated. The oscillation frequency of the packaged vibration piece 1 is measured by contacting the terminal of the package connected to the electrode pad 46 provided in 1. In the case of the vibration piece 1 formed on the large substrate, the frequency may be measured in a state where the vibration piece 1 is connected to the large substrate, the frequency is roughly adjusted, and then the pieces are separated and packaged. Further, the frequency may be roughly adjusted while connected to a large substrate, the lid may be joined to the upper surface in a vacuum state, and then the lid may be separated into individual pieces.

1.5 Frequency fine adjustment step Next, in step S5, the vibration piece 1 is adjusted to a target frequency of 32.768 kHz based on the oscillation frequency measured in step S4. For example, as shown in FIG. 10, by removing a part of the metal film 50 provided at the tips of the arms 22, 23, and 24 with a laser and adjusting the oscillation frequency of the vibrating piece 1 to a high value, about 32. The 700 kHz vibration piece 1 can be adjusted to a target frequency of 32.768 kHz.
By going through each of the above steps, the vibration piece 1 can be adjusted to a target frequency, for example, 32.768 kHz, which is a desired frequency.

In the present embodiment, the frequency coarse adjustment step and the frequency fine adjustment step are performed after the frequency measurement steps of steps S2 and S4, but the present invention is not limited to this, and the frequency coarse adjustment step and the frequency fine adjustment step are performed. In, the oscillation frequency of the vibration piece 1 may be adjusted while measuring the frequency. In particular, in the frequency fine adjustment step of step S5, if the frequency is adjusted while measuring the frequency, the metal film 50 can be removed more accurately by the laser, and the frequency can be adjusted with higher accuracy.

2. 2. Second Embodiment Next, the vibration piece 1a according to the second embodiment will be described with reference to FIG. 11. The same components as those of the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.
The vibrating piece 1a of the second embodiment is the same as the vibrating piece 1 of the first embodiment except that the configuration of the beam for frequency adjustment is different from that of the vibrating piece 1 of the first embodiment.

As shown in FIG. 11, the vibrating piece 1a connects two arms between the first arm 22a and the second arm 23a of the vibrating body 20a and between the second arm 23a and the third arm 24a. A plurality of frequency adjusting beams having different widths and spacings between adjacent beams are provided.

Specifically, the width of the first beam 61 in the lateral direction is W2, the distance between the first beam 61 and the adjacent beams is S2, and the distance between the first beam 61 and the second beam 62 is S2. Has the same width and spacing as the first beam 61. On the other hand, the width and spacing of the third beam 63, the fourth beam 64, and the fifth beam 65 are the same as the spacing S3 between the width W3 of the sixth beam 66 and the base 21.

Further, as described in the first embodiment, the width W1 and the interval S1 are each set to 1 μm, and by cutting, the total length L becomes 2 μm longer and the frequency of about 0.25 kHz can be lowered. Therefore, for example, the width W2 When the interval S2 is 2 μm, the total length L is increased by 4 μm by cutting the first beam 61, and the frequency of about 0.5 kHz can be lowered. When the second beam 62 is also cut, about 1. The frequency of 0 kHz can be lowered. Further, assuming that the width W3 and the interval S3 are 0.5 μm each, the total length L is increased by 1 μm by cutting the third beam 63, the frequency of about 0.125 kHz can be lowered, and the fourth beam 64 is also When disconnected, the frequency can be reduced by about 0.25 kHz. Therefore, by cutting the four beams from the third beam 63 to the sixth beam 66, the frequency of 0.5 kHz can be lowered.

With such a configuration, a beam for frequency adjustment with a wide width and a wide interval is arranged on the tip side of the arms 22a, 23a, 24a, and a beam for frequency adjustment with a narrow width and an interval is arranged on the base 21 side. Therefore, the frequency can be roughly adjusted by cutting the beam for frequency adjustment on the tip side, and then the frequency can be finely adjusted by cutting the beam for frequency adjustment on the base 21 side. A vibrating piece 1a having a large frequency adjustment amount can be obtained.

1,1a ... Vibration piece, 10 ... SOI substrate, 11 ... Silicon substrate, 11a ... Cavity, 12 ... Embedded oxide film, 13 ... Surface silicon layer, 20 ... Vibrating body, 21 ... Base, 22 ... First arm, 23 ... 2nd arm, 24 ... 3rd arm, 25 ... 1st beam, 25a ... 1st part, 25b ... 2nd part, 26 ... 2nd beam, 27 ... 3rd beam, 28 ... 4th beam, 29 ... 5 beams, 30 ... temperature characteristic adjusting film, 40 ... piezoelectric drive unit, 41 ... polysilicon film, 42 ... first electrode, 43 ... piezoelectric layer, 44 ... second electrode, 45 ... wiring, 46 ... electrode pad, 50 ... Metal film, 51 ... Cutting marks.

Claims (9)

At the base,
The first arm continuous with the base,
The second arm continuous with the base,
A first beam having a first portion connected to the first arm, a second portion connected to the second arm, facing the first portion, and located on an extension of the first portion. ,
The first electrode arranged on the first arm and the second arm,
The piezoelectric layer arranged on the first electrode and
The second electrode arranged on the piezoelectric layer and
Including vibrating pieces. The first beam is located between the base and the longitudinal center of the first arm and the second arm.
The vibrating piece according to claim 1. In addition to the first beam, it has one or more and seven or less beams.
The vibrating piece according to claim 1 or 2. The one or more and seven or less beams are arranged between the first beam and the base.
The vibrating piece according to claim 3. Each of the one or more and seven or less beams connects the first arm and the second arm, or is connected to the portion connected to the first arm and the second arm. It has a portion facing the portion connected to the first arm and located on an extension of the portion connected to the first arm.
The vibrating piece according to claim 3 or 4. A metal film having a cutting mark is arranged on the first arm and the second arm.
The vibrating piece according to any one of claims 1 to 5. It is a frequency adjustment method for vibrating pieces.
The vibrating piece is
At the base,
The first arm continuous with the base,
The second arm continuous with the base,
A first beam connecting the first arm and the second arm,
The first electrode arranged on the first arm and the second arm,
The piezoelectric layer arranged on the first electrode and
The second electrode arranged on the piezoelectric layer and
Including
The frequency adjustment method is
A step of changing the oscillation frequency of the vibrating piece by cutting the first beam.
including,
Frequency adjustment method. The vibrating piece comprises one or more beams disposed between the first beam and the base.
The frequency adjustment method is
The step of measuring the oscillation frequency of the vibrating piece and
A step of cutting the number of beams including the first beam and adjacent to each other according to the oscillation frequency.
including,
The frequency adjustment method according to claim 7. In the frequency adjustment method,
A step of lowering the oscillation frequency by cutting the first beam and the beam with a laser.
including,
The frequency adjustment method according to claim 8.

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